Assad: West is supporting 'terrorists'

Syrian President Bashar al-Assad claims the West is supporting 'terrorists' (Reuters)

Syrian President Bashar al-Assad has chided Western nations for "crying" over refugees flooding into Europe, claiming their support for "terrorists" lies at the roots of his country's crisis.

His remarks, on the eve of the UN peace envoy's visit to Damascus, came as Australia said it had joined the US-led air war against the Islamic State group in Syria, and France said it would as well.

Washington, meanwhile, told close Damascus ally Moscow that Assad has no role in the war against IS in Syria and must step down to allow a political settlement.

Assad, according to a transcript made available on Wednesday, said refugees were leaving Syria "mainly because of the terrorists and because of the killing, and second because of the results of terrorism".

"When you have terrorism, and you have the destruction of the infrastructure, you won't have the basic needs of living.

"So, the West is crying for them, and the West is supporting terrorists since the beginning of the crisis when it said that this was a peaceful uprising," Assad said.

"If you are worried about them, stop supporting terrorists."

Damascus labels all those involved in the war against Assad as "terrorists", including Western-backed rebels.

In Washington, US Secretary of State John Kerry warned that Russia's backing for Assad risked further escalating the conflict

In Sydney, meanwhile, Defence Minister Kevin Andrews said Australian warplanes had carried out their first strike against IS in Syria, destroying an armoured personnel carrier on Monday.

Australia joined the US-led coalition fighting IS in Iraq last year.

The United States, Canada, Turkey and Gulf states have already been involved in strikes in Syria, while France has been carrying out surveillance flights in preparation to do so as well.